T Harris wrote:
> How can I get Mathematica to find the area of the region bounded by all
> three of the following linear functions? I have tried searching and can't
> find it. What do I search for to find the commands to accomplish this? I
> calculated by hand and come up with about 3.1623 sq. units for area above
> the x-axis and 8.8378 sq. units below it. The total area for the scalene
> triangle formed is 12 square units by my calculations using Heron's formula.
>
> X=3Y; X+Y=0; 7X + 3Y =24
In[1]:= 1/2 Abs@Det[ Flatten[{x,y,1}/.Solve[#,{x,y}]]& /@
Subsets[{x == 3y, x + y == 0, 7x + 3y == 24}, {2}] ]
Out[1]= 12